package com.hmdp.utils;

import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import javax.annotation.Resource;
import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;


@Component
public class RedisIdWorker {
    // 开始时间戳
    public static final long BEGIN_TIMESTAMP = 1735689600L;
    // 序列号的位数
    public static final int COUNT_BITS = 32;

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    public RedisIdWorker(StringRedisTemplate stringRedisTemplate) {
        this.stringRedisTemplate = stringRedisTemplate;
    }

    public long nextId(String keyPrefix){
        // 1.生成时间戳
        LocalDateTime now = LocalDateTime.now();
        long nowSecond = now.toEpochSecond(ZoneOffset.UTC);
        long timestamp = nowSecond - BEGIN_TIMESTAMP;

        // 2.生成序列号
        // (1)获取当前日期，精确到天
        String day = now.format(DateTimeFormatter.ofPattern("yyyy-MM-dd"));
        // (2)自增长
        long count = stringRedisTemplate.opsForValue().increment("icr" + keyPrefix + ":" + day);

        // 3.拼接并返回
        return timestamp << COUNT_BITS | count;
    }
}
